1. Field of the Invention
This invention relates to a classification accuracy setting device and a method therefor of a coin selector used in an automatic vending machine, a money exchanger and other various automatic service apparatuses.
2. Description of the Related Art
The coin selector has two types, mechanical type and electronic type. The mechanical type mechanically checks the property of a coin and classifies the coin according to its denomination, and the electronic type electronically detects the property of a coin and classifies the coin according to its denomination on the basis of the resulting detection output. The use of the electronic type coin selector has been more common because the electronic type coin selector has a higher classification accuracy and a smaller size.
One example of the electronic type coin selector has a coil provided at one side of a coin passageway and energized in response to a signal of a predetermined frequency, compares a frequency shift or an attenuated voltage waveform caused by the coil when a coin passes past the coil with a reference value corresponding to a predetermined classification accuracy in order to determine whether the received coin is true or false and the kind of the received coin, and classifies the coin on the basis of the result of the determination.
Another example of the electronic type coin selector has an oscillating coil which is provided at one side of a coin passageway and energized in response to a signal of a predermined frequency, and a receiving coil which is provided at the other side of the coin passageway and electromagnetically coupled with the energized oscillating coil, compares an attenuated voltage waveform caused by the receiving coil when a coin passes between the oscillating and receving coils with a reference value corresponding to a predetermined classification accuracy in order to determine whether the received coin is true or false and the kind of the received coin, and classifies the coin on the basis of the result of the determination.
These electronic type coin selectors can select the reference values so as to moderate and make strict determination criteria for determining whether the received coin is true or false and the kind of the coin.
The conventional coin selector is so arranged that the reference values of the classification accuracies are set by varying a value of each of variable resistors at the time of assembling.
However, with this arrangement, there has been a problem that the classification accuracies cannot easily be changed by a routeman or a supervisor of a vending machine when he desires to slightly moderate or make strict the classification accuracies in order to eliminate false coins, since it is difficult to adjust the values of the variable resistors for determining desired levels of the classification accuracies.
An object of the present invention is to provide a classification accuracy setting device and a method therefor of a coin selector of which the classification accuracy can be easily changed.